摘要
碱抽提玉米秸秆纤维素乙醇残渣制备木素,研究了乙醇、甲醛、丙三醇封端剂对木素碱催化解聚体系中解聚产物分布及封端效应的影响。结果表明,纯水体系及乙醇、甲醛、丙三醇封端剂均能在碱性条件下解聚木素,且不同封端剂对解聚产物选择性不同。丙三醇对酚类产物选择性优于乙醇和甲醛,而甲醛能够减少酚类产物种类,说明不同封端剂对木素活性中间体封端位置具有一定选择性。另外,催化解聚后残余木素平均相对分子质量显著降低,其热失重温度范围明显分为低温区和高温区,说明残余木素既含有较弱的类似醚键的连接键也含有大量芳香环类C—C连接键。
The lignin was prepared by alkali extraction of cellulose residue from corn stover at room temperature. The effects of different capping agents such as ethanol, formaldehyde and glycerol on the distribution and capping effect of depolymerization products in lignin-catalyzed depolymerization system were studied. The results showed that the alkali-catalyzed depolymerization system of pure water system and ethanol, formaldehyde and glycerol end-capping agents had certain depolymerization effect on lignin. The selectivity of glycerol to phenolic products was better than that of ethanol and formaldehyde, and formaldehyde could reduce the composition of phenolic products. The phenolic compounds obtained by the three kinds of blocking agent system were identical isomers, of which had a certain selectivity to the end position of lignin active intermediates. The average relative molecular weight of residual lignin decreased significantly after alkali-catalyzed desorption by blocking agent, and its thermogravimetric temperature range divided to two parts as low temperature region and high temperature region, indicating that residual lignin contained weak ether-like linkage and a large number of aromatic ring C--C link keys as well.
作者
蒲磊
王兴
周景辉
PU Lei WANG Xing ZHOU Jinghui(School of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China)
出处
《大连工业大学学报》
CAS
北大核心
2017年第4期265-270,共6页
Journal of Dalian Polytechnic University
基金
国家自然科学基金项目(31470604)
关键词
木素
玉米秸杆
碱催化解聚
封端剂
lignin~ corn stover
alkali catalyzed depolymerization
capping agent
